Unified input/output interface for electronic device

ABSTRACT

Components associated with receiving user touch input, receiving user force input, and providing haptic output interface are integrated into a unified input/output interface that includes a transducer substrate formed with a monolithic or multi-layer body having a number of electrodes disposed on surfaces thereof. Electrodes are selected by a controller to provide touch input sensing, force input sensing, and haptic output.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a non-provisional patent application of, and claimsthe benefit to, U.S. Provisional Patent Application No. 62/548,293,filed Aug. 21, 2017, and titled “Unified Input/Output Interface forElectronic Devices,” the disclosure of which is hereby incorporatedherein by reference in its entirety.

FIELD

Embodiments described herein relate to electronic devices, and inparticular, to electronic devices that incorporate an interface toreceive touch and force input from a user, and, additionally, to providehaptic output to that user.

BACKGROUND

An electronic device can include an input sensor to detect when a usertouches a surface of the electronic device to provide a “touch input” tothe electronic device. Such sensors, together with associated circuitryand structure, can be referred to as “touch input sensors.”

Additionally, an electronic device can include an input sensor to detectwhen the user applies a purposeful force to a surface of the electronicdevice to provide a “force input” to the electronic device. Suchsensors, together with associated circuitry and structure, can bereferred to as “force input sensors.”

An electronic device can also include a mechanical actuator to generatea mechanical output through a surface of the electronic device toprovide a “haptic output” to the user. Such actuators, together withassociated circuitry and structure, can be referred to as “hapticactuators.”

In conventional configurations, however, touch input sensors, forceinput sensors, and haptic actuators are separately controlled andoperated, and independently contribute to undesirable increases inthickness, weight, power consumption, and manufacturing complexity of anelectronic device.

SUMMARY

Embodiments described herein generally reference an electronic devicethat includes a unified input/output interface. The unified input/outputinterface is implemented with a transducer substrate including a bodyformed from a dielectric material that induces anelectrically-measurable response when compressed, such as apiezoelectric material. The transducer substrate also includes a set ofelectrodes disposed on a first surface of the body. A shared groundelectrode is disposed onto a second surface of the body opposite thefirst surface. A haptic actuator, such as a stack actuator, is disposedbelow—and coupled to—the shared ground electrode.

In further embodiments, the unified input/output interface includes acontroller configured to selectively activate the haptic actuator, andone or more electrodes of the set of electrodes in order to transitionto, without limitation: a touch sensing mode; a force sensing mode; ahaptic output mode; a touch and force sensing mode; a touch sensing andhaptic output mode; a force sensing and haptic output mode; and so on.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to representative embodiments illustrated inthe accompanying figures. It should be understood that the followingdescriptions are not intended to limit this disclosure to one preferredembodiment. To the contrary, the disclosure provided herein is intendedto cover alternatives, modifications, and equivalents as may be includedwithin the spirit and scope of the described embodiments, and as definedby the appended claims.

FIG. 1 depicts an electronic device incorporating a unified input/outputinterface, such as described herein.

FIG. 2A depicts an assembly view of the unified input/output interfaceof FIG. 1.

FIG. 2B depicts a bottom, assembled view of the unified input/outputinterface of FIG. 2A.

FIG. 2C depicts a cross-section of the unified input/output interface ofFIG. 2B, taken through line A-A.

FIG. 2D depicts another cross-section of the unified input/outputinterface of FIG. 2B, taken through line B-B.

FIG. 3A depicts a simplified system diagram and cross-section of oneexample unified input/output interface, such as described herein.

FIG. 3B depicts a simplified system diagram and cross-section of anotherexample unified input/output interface, such as described herein.

FIG. 3C depicts a simplified system diagram and cross-section of yetanother example unified input/output interface, such as describedherein.

FIG. 4 depicts a finite state diagram corresponding to an operationalconfiguration of a unified input/output interface, such as describedherein.

FIG. 5A depicts an example distribution of electrodes for a unifiedinput/output interface, such as described herein.

FIG. 5B depicts another example distribution of electrodes for a unifiedinput/output interface, such as described herein.

FIG. 5C depicts another example distribution of electrodes for a unifiedinput/output interface, such as described herein.

FIG. 6 depicts a system diagram of an integrated circuit that can beconfigured to control and/or operate a unified input/output interface,such as described herein.

FIG. 7 depicts a flowchart including example operations of a method ofreceiving touch and force input with a unified input/output interface,such as described herein.

FIG. 8 depicts a flowchart including example operations of a method ofproviding haptic output with a unified input/output interface, such asdescribed herein.

FIG. 9 depicts a flowchart including example operations of a method ofcalibrating the haptic output of a unified input/output interface, suchas described herein.

The use of the same or similar reference numerals in different figuresindicates similar, related, or identical items.

The use of cross-hatching or shading in the accompanying figures isgenerally provided to clarify the boundaries between adjacent elementsand also to facilitate legibility of the figures. Accordingly, neitherthe presence nor the absence of cross-hatching or shading conveys orindicates any preference or requirement for particular materials,material properties, element proportions, element dimensions,commonalities of similarly illustrated elements, or any othercharacteristic, attribute, or property for any element illustrated inthe accompanying figures.

Additionally, it should be understood that the proportions anddimensions (either relative or absolute) of the various features andelements (and collections and groupings thereof) and the boundaries,separations, and positional relationships presented therebetween, areprovided in the accompanying figures merely to facilitate anunderstanding of the various embodiments described herein and,accordingly, may not necessarily be presented or illustrated to scale,and are not intended to indicate any preference or requirement for anillustrated embodiment to the exclusion of embodiments described withreference thereto.

DETAILED DESCRIPTION

Embodiments described herein reference an electronic device thatincludes a unified input/output interface. The phrase “unifiedinput/output interface,” as used herein, generally references a systemor set of components configured to (1) receive touch input and forceinput at a surface from a user and, additionally, (2) configured toprovide haptic output to that same user through the same surface. Thesurface associated with a unified input/output interface, such asdescribed herein, that may be touched by a user is referred to as an“interface surface.”

In one example, a unified input/output interface is associated with anactive display region of a display of an electronic device, such as atablet computer or mobile phone. In this example, the interface surfaceis positioned above the active display region. The unified input/outputinterface can be positioned above, below, adjacent to, or along aperimeter of the display. In some cases, the unified input/outputinterface is integrated into the display. The interface surfaceassociated with the unified input/output interface can be formed from anopaque or transparent material such as metal, glass, organic materials,synthetic materials, woven materials, and so on. In typical examples,the interface surface is a dielectric material, but this may not berequired of all embodiments.

The unified input/output interface includes a monolithic or multi-layersubstrate, referred to herein as a “transducer substrate.” Thetransducer substrate is typically disposed below the interface surfaceand is positioned above, below, adjacent to, or along a perimeter of theactive display region of the display. In some cases, an exterior surfaceof the transducer substrate defines the interface surface; a separateinterface surface is not required. The unified input/output interfacealso includes two or more electrodes disposed onto surfaces of thetransducer substrate. In one example, a transducer substrate receives afirst array of electrodes on a top surface and a second array ofelectrodes on a bottom surface. The electrodes are electrically coupledto a controller of the unified input/output interface.

As a result of this construction, a user can touch the interface surfaceto instruct the electronic device to perform an action. The location(s)of the touch(es) can be detected by the unified input/output interfaceby operating one or more electrodes of the unified input/outputinterface as a capacitive sensor.

Alternatively or additionally, the user can exert a force onto theinterface surface to instruct the electronic device to perform anaction. The location(s) and/or magnitude(s) of the force input(s) can bedetected by the unified input/output interface by operating one or moreelectrodes of the unified input/output interface as a compression orstrain sensor.

Further, in response to receiving/detecting a touch input and/or a forceinput, the unified input/output interface can generate a haptic outputthrough the interface surface at, or near, the location of the detectedinput to inform the user that the input was received, that an action wasor will be performed, or for any other suitable notification or userexperience purpose. In this operational mode, the unified input/outputinterface operates one or more electrodes as a drive electrode of ahaptic actuator.

The preceding example embodiment is merely one example. For simplicityof description, many embodiments that follow reference a unifiedinput/output interface operated in conjunction with a non-display regionof an electronic device, such as a trackpad input region of a laptopcomputer. However, it is understood that a unified input/outputinterface, such as described below, can be suitably integrated into, orassociated with, any surface of any electronic device, including but notlimited to: display surfaces; non-display surfaces; housing surfaces;peripheral input device surfaces; front surfaces; back surfaces;sidewall surfaces; accessible interior surfaces; planar surfaces; curvedsurfaces; and so on.

A unified input/output interface, such as described herein, can beconstructed in a number of ways. As noted above, a unified input/outputinterface includes a transducer substrate that can be operated toreceive both touch input and force input and, additionally, can beoperated to generate haptic output. A transducer substrate is typicallyimplemented with a monolithic or multi-layered body formed into a planarsheet or layer from one or more materials that expand or contract inresponse to an electrical signal, such as piezoelectric materials,electroactive polymers, magnetostrictive materials, and so on. The bodyof the transducer substrate defines a top surface and a bottom surface(opposite the top surface) that are configured to receive one or moreelectrodes, or sets of electrodes.

In one example construction, a top electrode is disposed onto the topsurface of the body of the transducer substrate and a bottom electrodeis disposed onto the bottom surface of the body of the transducersubstrate. In a “touch sensing mode,” the unified input/output interfacecan be configured to operate the top electrode and/or the bottomelectrode as a capacitive touch and/or presence sensor. In a “forcesensing mode,” the unified input/output interface can be configured todetect or otherwise measure a voltage between the top electrode and thebottom electrode that occurs as a result of compression (or relief fromcompression) of the body. In a “haptic output mode,” the unifiedinput/output interface can be configured to apply a voltage across thebody, between the top electrode and the bottom electrode to cause thebody to mechanically expand or contract.

In other embodiments, more than one electrode can be disposed onto thebody of the transducer substrate in an array, grid, or pattern. Forexample, the top electrode referenced above can be segmented into a gridof individual electrodes. In another example, the top electrodereferenced above can be segmented into a set of column electrodes andthe bottom electrode referenced above can be segmented into a set of rowelectrodes, oriented perpendicular to the column electrodes. These aremerely examples; it is appreciated that any number of patterns,orientations, and/or segmentations of one or more electrodes can bedisposed onto a transducer substrate of a unified input/outputinterface, such as described herein.

In certain embodiments, the body of the substrate can be formed frommultiple purpose-configured layers. For example, in one embodiment, abody may be formed with a force-sensing layer and a haptic output layer.The force-sensing layer can define the top surface that receives a firstset of electrodes and the haptic output layer can define the bottomsurface that receives a second set of electrodes. The force-sensinglayer can be separated from the haptic output layer by a shared groundelectrode layer. In some examples, the force-sensing layer and thehaptic output layer can be formed from the same piezoelectric materialto the same dimensions, but this is not required. In some cases, theforce-sensing layer may be thinner than the haptic output layer. In somecases, the force-sensing layer can be formed from a first piezoelectricmaterial and the haptic output layer can be formed from a secondpiezoelectric material. In other examples, other constructions and layerconfigurations are possible.

As noted above, a unified input/output interface, such as describedherein, also includes—or is associated with—a controller electricallycoupled to the transducer substrate via the one or more electrodesdisposed on one or more surfaces of the body of the transducersubstrate. The controller can include, or can be communicably coupledto, circuitry and/or logic components, such as a processor. Thecircuitry can perform or coordinate some or all of the operations of thecontroller including, but not limited to: providing a signal to generatea haptic output (herein, “haptic drive signals”); receiving a signalassociated with a force input received from a user (herein, “force sensesignals”); receiving a signal associated with a touch input receivedfrom a user (herein, “touch sense signals”); filtering sense signalsbased on one or more haptic drive signals; characterizing a hapticoutput—generated in response to a haptic drive signal—based on a touchor force sense signal; and so on.

The processor of the controller can be implemented as any electronicdevice(s) or component(s) capable of processing, receiving, ortransmitting data or instructions in an analog and/or digital domain.For example, the processor can be a microprocessor, a central processingunit, an application-specific integrated circuit, a field-programmablegate array, a digital signal processor, an analog circuit, a digitalcircuit, or combination of such devices. The processor may be asingle-thread or multi-thread processor. The processor may be asingle-core or multi-core processor. Accordingly, as described herein,the term “processor” refers to a hardware-implemented data processingdevice or circuit physically structured to execute specifictransformations of data including data operations represented as codeand/or instructions included in a program that can be stored within andaccessed from an integrated or separate memory. The term or phrase ismeant to encompass a single processor or processing unit, multipleprocessors, multiple processing units, analog or digital circuits, orother suitably configured computing element or combination of elements.

As noted above, a transducer substrate, such as described herein, can beconfigured to operate in multiple modes, independently orsimultaneously. More specifically, a transducer substrate can beoperated in a “sense mode” in which one or more force inputs and/ortouch inputs can be received and measured and a “drive mode” in whichone or more haptic outputs can be generated. In certain embodiments, atransducer substrate can be operated in a “hybrid mode” in which one ormore haptic outputs are provided while a force input and/or a touchinput is received.

These and other embodiments are discussed below with reference to FIGS.1-9. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanation only and should not be construed as limiting.

FIG. 1 shows an electronic device 100 that can include a unifiedinput/output interface, such as described herein. As with otherembodiments, the unified input/output interface can be configured toreceive touch and/or force input from a user and to provide hapticoutput to that same user through the same surface. More particularly,the unified input/output interface is formed as a single substrate orcomponent, from one or more layers. As a result of this construction,the unified input/output interface is substantially thinner than aconventional implementation that includes separate touch input sensors,force input sensors, and haptic actuators.

In the illustrated embodiment, the unified input/output interface isassociated with an input area accommodated in an enclosure 102 of theelectronic device 100. In the illustrated example, the unifiedinput/output interface (described in greater detail below) is positionedin the conventional location of a trackpad area, subjacent to a keyboarddisposed in a lower portion of a foldable enclosure of a laptopcomputer. In other examples, the unified input/output interface can beincluded in, or within, without limitation: a primary or secondarydisplay region of the electronic device 100; a non-display region of theelectronic device 100; a rear housing plate of the enclosure 102 of theelectronic device 100; a biometric input region of the electronic device100; keys of the keyboard of the electronic device 100; buttons of theelectronic device 100; and so on.

Further, it may be appreciated that the depicted embodiment is merelyone example and that other implementations of unified input/outputinterfaces can be integrated into, associated with, or take the form ofdifferent components or systems of other electronic devices including,but not limited to: desktop computers; tablet computers; cellularphones; wearable devices; peripheral devices; input devices; accessorydevices; cover or case devices; industrial or residential control orautomation devices; automotive or aeronautical control or automationdevices; a home or building appliance; a craft or vehicle entertainment,control, and/or information system; a navigation device; and so on.

The enclosure 102 is configured to retain, support, and/or enclosevarious electrical, mechanical, and structural components of theelectronic device 100, including, for example, a display 104 and aunified input/output interface 106. The enclosure 102 can be formed, asan example, from glass, sapphire, ceramic, metal, fabric, polymerizedfiber, plastic, or any combinations thereof.

The electronic device 100 can also include a processor, memory, powersupply and/or battery, network connections, sensors, input/outputcomponents, acoustic elements, haptic actuators, digital and/or analogcircuits for performing and/or coordinating tasks of the electronicdevice 100, and so on. For simplicity of illustration, the electronicdevice 100 is depicted in FIG. 1 without many of these elements, each ofwhich may be included, partially or entirely, within the enclosure 102and may be operationally, structurally, or functionally associated with,or coupled to, the unified input/output interface 106.

As with many embodiments described herein, the unified input/outputinterface 106 is configured to detect touch input and force input and,additionally, is configured to operate in a touch sensing mode, a forcesensing mode, a haptic output mode, and/or a hybrid mode in which hapticoutput is provided while force and/or touch input is received. In manycases, the touch input and force input can be provided to interact withcontent shown in a graphical user interface presented on the display104, but it is appreciated that user input can be provided for otherpurposes as well.

The unified input/output interface 106 can be constructed in a number ofways, some of which are described in reference to FIGS. 2A-2D and 3A-3C.Independent of the particular construction or configuration selected fora particular embodiment of the unified input/output interface 106, it isappreciated that—as described above—the unified input/output interface106 typically includes a single or multi-layer transducer substrate thatdefines (or is positioned below) an interface surface to receive touchand force input from the user 108. The transducer substrate typicallyincludes a body formed from at least one layer of compressible materialthat produces an electrically-measurable response upon being compressed(e.g., change in resistance, change in capacitance, change ininductance, voltage production, charge production, and so on). Thetransducer substrate also includes at least one layer of electrodesdisposed onto a surface of the compressible material of the body. Byselectively coupling the electrodes of the transducer substrate to touchand/or force sensing circuitry (more simply, “sense circuitry”), touchinput and force input can be detected. By selectively coupling theelectrodes of the transducer substrate to haptic output circuitry (moresimply, “drive circuitry”), haptic outputs can be provided. In thismanner, the transducer substrate of the unified input/output interface106 selectively operates the same physical structure and the sameelectrode pattern(s) for multiple, distinct input/output purposes.

More particularly, in a touch sensing mode, the unified input/outputinterface 106 of the electronic device 100 can be configured todetermine a location of or one or more touches (e.g., single touch ormulti-touch) to the interface surface by monitoring for changes incapacitance at one or more of the electrodes disposed on the surface ofthe body of the transducer substrate. The unified input/output interface106 can operate according to any suitable capacitance or chargemonitoring technique such as, but not limited to: mutual capacitivesensing; self-capacitive sensing; projected capacitance sensing; and soon. Additionally or alternatively, the unified input/output interface106 can be configured to determine a touch gesture such as, but notlimited to: a slide gesture; a rotate gesture; a pinch gesture; anexpand gesture; multi-figure gestures; a swipe gesture; and so on.

In a force sensing mode, the unified input/output interface 106 can beconfigured to determine a location and/or a magnitude of one or moreforce inputs (e.g., single force or multi-force) to the interfacesurface by monitoring for changes in voltage between two or more of theelectrodes disposed on the surface of the body of the transducersubstrate. The unified input/output interface 106 can operate accordingto any suitable voltage monitoring technique. Additionally oralternatively, the unified input/output interface 106 can be configuredto determine a force gesture such as, but not limited to: a hard press;a soft press; a force drag; a down-stroke threshold crossing; anup-stroke threshold crossing; and so on.

In a haptic output mode, the unified input/output interface 106 can beconfigured to apply a local, semi-local, or global haptic output throughthe interface surface by applying a voltage between two or more of theelectrodes disposed on the surface of the body of the transducersubstrate. In response to the voltage, the piezoelectric material of thebody can compress or expand, inducing a bending moment into theinterface surface and producing a haptic output. The haptic output canbe any suitable haptic output such as, but not limited to: a tap orseries of taps; a vibration; a static expansion; a static compression;and so on.

In a hybrid mode, the unified input/output interface 106 can beconfigured to apply a local, semi-local, or global haptic output throughthe interface surface by applying a voltage between two or more of theelectrodes disposed on the surface of the body of the transducersubstrate. Simultaneously, the unified input/output interface 106 isconfigured to detect and quantify touch and/or force input by measuringa capacitance or voltage associated with the same or differentelectrodes disposed on the surface of the body of the transducersubstrate. In many examples, haptic output and input detection can betime-multiplexed whereas in other cases, the transducer substrate mayinclude more than one layer that can be simultaneously operated, such asa haptic output layer and a force input layer.

FIG. 2A depicts an assembly view of one example stack of layers thatcooperate to define a unified input/output interface, such as theunified input/output interface 106 of FIG. 1. In this illustration, theinterface is identified as the unified input/output interface 200.

In this embodiment, the unified input/output interface 200 is formedfrom multiple layers of material into a single unified stack. Moreparticularly, in this example, the unified input/output interface 200includes an outer cover layer 202 that is coupled, via an adhesive layer204, to a routing insulator layer 206. A compression-sensitive layer 208is positioned below the routing insulator layer 206. Four haptic stackactuators, each identified as a haptic stack actuator 210, arepositioned below compression-sensitive layer 208 and aligned withcorners of the compression-sensitive layer 208. The haptic stackactuators 210 are adhered to the compression-sensitive layer 208 viaadhesives, identified as the adhesive regions 212, and/or via mechanicalfasteners, such as the fastener/stiffeners identified in the figure asthe stiffener 214. Assembled views and cross-sections of the unifiedinput/output interface 200 are provided in FIGS. 2B-2D.

The outer cover layer 202 of the unified input/output interface 200defines the interface surface that is touched by the user. The outercover layer 202 can be formed from a number of materials including, butnot limited to: glass, plastic, woven materials, synthetic materials,organic materials, and so on. In many cases, the outer cover layer 202is substantially planar, but this is not required. The outer cover layer202 can also include one or more aesthetic and/or cosmetic layers suchas, but not limited to: ink layers; glyph layers; light guide regions;and so on.

As illustrated, the compression-sensitive layer 208 of the unifiedinput/output interface 200 is positioned below the outer cover layer202, separated by the adhesive layer 204 and the routing insulator layer206, discussed in greater detail below. As a result of thisconstruction, the outer cover layer 202 serves to protect and/orencapsulate subordinate layers of the unified input/output interface200. In some embodiments, the outer cover layer 202 can be disposed towrap around edges/sidewalls of the unified input/output interface 200 toprovide further insulation, encapsulation, or protection to the unifiedinput/output interface 200. In some examples, the outer cover layer 202completely encapsulates the unified input/output interface 200.

FIG. 2C depicts a cross-section of the unified input/output interface200 taken through line A-A, in particular showing thecompression-sensitive layer 208 and the haptic stack actuators 210. FIG.2D depicts a cross-section of the unified input/output interface 200taken through line B-B, in particular showing the adhesive regions 212and the stiffeners 214.

In these examples, the compression-sensitive layer 208 includes a senseelectrode array 216 and a ground electrode 218 that are separated by abody. As illustrated, the body is monolithic, but this may not berequired; the body can be formed from multiple individual layers.

The sense electrode array 216 and the ground electrode 218 are formedfrom electrically conductive materials disposed onto the body of thecompression-sensitive layer 208. In many cases, the sense electrodearray 216 and the ground electrode 218 can be formed from the samematerial but this may not be required. Suitable materials for theelectrodes include, but are not limited to: copper; gold; silver;titanium; and so on.

In one embodiment, the body is formed from a piezoelectric crystallinematerial that is configured to develop a measurable charge (between thesense electrode array 216 and the ground electrode 218) in response tocompression or strain that results from a force applied to the outercover layer 202. Suitable piezoelectric materials include, but may notbe limited to lead-based piezoelectric alloys (e.g., lead zirconatetitante) and non-leaded materials such as metal niobates or bariumtitanate. In other examples, single layer or multi-layer otherpiezoelectric compositions can be selected.

In other embodiments, the body of the compression-sensitive layer 208 isformed from another material such as, but not limited to: electroactivepolymers; ferrofluid materials; magnetostrictive materials;piezoresitive materials; and so on. For simplicity of description, thebody of the compression-sensitive layer 208 as described below may beconsidered to be formed from a piezoelectric material, but it isunderstood that this is merely one example. Similarly, the structuraland/or functional configuration or implementation of the embodimentsthat follow may be appropriately modified based on the material(s)selected for the body of the compression-sensitive layer 208.

The sense electrode array 216 of the compression-sensitive layer 208includes a number of individual sense electrodes (not visible in thesimplified cross-sections shown) distributed across thecompression-sensitive layer 208 in an array or pattern. Exampleelectrode distributions and/or electrode patterns are shown anddescribed in reference to FIGS. 5A-5C. Each individual sense electrodeof the sense electrode array 216 is electrically coupled, via a traceformed on multiple surfaces of and/or through the routing insulatorlayer 206, to sensor circuitry such as touch sensor circuitry and/orforce sensor circuitry to detect touch and/or force inputs to the outercover layer 202.

In particular, in a touch sensing mode, the individual sense electrodeof the sense electrode array 216 can be driven—via alternating currentor direct current or any suitable waveform—to a particular voltagepotential, biasing the electrode to a particular positive or negativecharge. As a user's finger approaches one (or more) individual senseelectrode of the sense electrode array 216, the charge of nearbyelectrodes will measurably change. Once a change or absolute value ofcharge (or voltage, phase, time-averaged amplitude, and so on) beyondthreshold is detected, a touch event can be reported to a processor incommunication with the unified input/output interface 200. The touchevent can include touch position information, touch area information,touch gesture information, and so on. The touch event can be associatedwith one or more independent touch locations, gestures, or areas. Thetouch event can also include derivative information such as changes inarea or location over time.

In other cases, other methods apart from self-capacitance can be used bythe unified input/output interface 200 to detect one or more touches ofa user such as, but not limited to: mutual capacitance between adjacentor vertically-aligned electrodes (e.g., in some embodiments the groundelectrode 218 may be segmented); projected capacitance; and so on.Broadly, it is understood that the electrodes of the sense electrodearray 216 can be used in any suitable manner to detect a user touch viacapacitive sensing.

Similarly, in a force sensing mode, the individual sense electrode ofthe sense electrode array 216 can be monitored to determine whethervoltage between the electrode and a reference voltage (e.g., ground) haschanged. As a user's finger applies a compressive force to one or moreindividual sense electrode of the sense electrode array 216, the chargeof the piezoelectric body nearby those electrodes may increase orotherwise change. Once a change or absolute value of charge (or voltage,phase, time-averaged amplitude, and so on) beyond threshold is detected,a force event can be reported to a processor in communication with theunified input/output interface 200. The force event can include forcemagnitude information, force directivity information, force positioninformation, touch area information, force gesture information, and soon. The force event can be associated with one or more independent forcelocations, gestures, or areas. As with the touch sensing mode, the forcecan also include derivative information such as changes in forcemagnitude, direction, or location over time.

Similarly, in a hybrid sensing mode, a first subset of the individualsense electrode of the sense electrode array 216 can be selected tomonitor for touch events whereas another subset of the individual senseelectrodes of the sense electrode array 216 can be selected to monitorfor force events. In this manner, both force and touch input events canbe captured simultaneously. In another example, an electrode can be usedto monitor for touch events during a first time period and used tomonitor for force events during a second time period. It may beappreciated that any suitable time-multiplexing and/or selectionalgorithm or technique can be used to detect touch and force inputssubstantially simultaneously.

As noted above, the unified input/output interface 200 is alsoconfigured to provide haptic output. The haptic stack actuators 210 ofthe unified input/output interface 200 can be actuated to provide hapticfeedback to the user through the outer cover layer 202. In particular,each haptic stack actuator 210 in the illustrated example is formed fromfive layers of electrically-expandable and/or electrically-compressiblematerial. In one specific example, each haptic stack actuator 210 is apiezoelectric stack actuator.

The layers of the haptic stack actuator 210 can be simultaneously orindependently actuated or driven (e.g., via an application of voltage)to generate a mechanical output through the outer cover layer 202. Inmany embodiments, the haptic stack actuators 210 are electricallycoupled to the ground electrode 218. As a result of this construction,the haptic stack actuators 210 are configured to share a common groundwith the compression-sensitive layer 208, thereby reducing themanufacturing complexity and stack height of the unified input/outputinterface 200.

The material(s) selected for the various layers (if more than one isrequired) of the haptic stack actuators 210 can be any suitable materialor combination of materials. For example, in one embodiment, each layerof each of the haptic stack actuators 210 is formed from a piezoelectricmaterial. In other examples, the electrically-expandable and/orelectrically-compressible material of each layer of each of the hapticstack actuators 210 is another material or structure such as, but notlimited to: electroactive polymers; magnetostrictive materials;voice-coin structures; and so on.

In some cases, each layer of each of the haptic stack actuators 210 isformed to the same thickness and of the same material (or in the samestructure), but this is not required; some layers may be thicker orshaped in a different manner than other layers. Further, in some cases,adjacent layers of each of the haptic stack actuators 210 can shareelectrodes, such as ground electrodes or drive electrodes. Moreparticularly, in the illustrated embodiment, the electrodes (notlabeled) separating each layer of each of the haptic stack actuators 210can alternate between ground electrodes and drive electrodes. As aresult of this construction, adjacent layers of the haptic stackactuators 210 are configured to share a common ground and/or a commondrive electrode, thereby reducing the manufacturing complexity and stackheight of the unified input/output interface 200.

In the illustrated embodiment, the haptic stack actuators 210 have athickness that is approximately two-and-one-half times that of thecompression-sensitive layer 208, but this may not be required. In oneexample, the haptic stack actuators 210 have a thickness ofapproximately 0.5 mm and the compression-sensitive layer 208 has athickness of approximately 0.2 mm.

As illustrated, the haptic stack actuators 210 are disposed along theperiphery of the unified input/output interface 200, but in someembodiments this may not be required. For example, in someconstructions, the unified input/output interface 200 can include one ormore haptic stack actuators in other locations and that take othershapes or thicknesses.

As illustrated, the haptic stack actuators 210 are illustrated as havinga quartered elliptical shape. In one embodiment, the foci of the ellipsethat defines the shape of the haptic stack actuators 210 areproportionately related to the dimensions of the unified input/outputinterface 200. For example, in one embodiment, the foci of an ellipsethat defines the shape of the haptic stack actuators 210 is related to(e.g., proportional) the ratio of length to width of a rectangular orrectilinear unified input/output interface. For example, a square-shapedunified input/output interface may include haptic stack actuators havinga quartered-circle shape whereas a unified input/output interface havinga length much greater than a width may include haptic stack actuatorsdefined by an ellipse having a more distant focal point than illustratedin FIGS. 2A-2B.

In still further examples, the haptic stack actuators 210 can takeanother shape such as, but not limited to: quartered or whole roundshapes; rectilinear shapes; triangular shapes; quartered or wholepolygonal shapes; quartered or whole arbitrary shapes; and so on.

It may be appreciated that the foregoing description of FIGS. 2A-2D, andvarious alternatives thereof and variations thereto are presented,generally, for purposes of explanation, and to facilitate a thoroughunderstanding of various possible configurations of an interdigitatedmultimode transducer substrate of a unified input/output interface.However, it will be apparent to one skilled in the art that some of thespecific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, the foregoing and following descriptions and specific embodimentsare understood to be presented for the limited purposes of illustrationand description. These descriptions are not targeted to be exhaustive orto limit the disclosure to the precise forms recited herein. To thecontrary, it will be apparent to one of ordinary skill in the art thatmany modifications and variations are possible in view of the aboveteachings.

Generally and broadly, FIGS. 3A-3C depict example configurations of aunified input/output interface. In these examples, a transducersubstrate is depicted in cross-section. As noted with respect to otherembodiments described herein, the unified input/output interfacesdepicted and described with respect to these figures are each associatedwith at least one electrical circuit, generally referred to as acontroller. The controller of these embodiments is understood to includeboth drive circuitry (configured to generate drive signals) and sensecircuitry (configured to detect sense signals) in a single integratedcircuit package, although in some cases, such circuitry may befunctionally or physically separated.

In particular, FIG. 3A depicts a simplified system diagram of oneexample unified input/output interface, identified as the unifiedinput/output interface 300 a. In this example, the unified input/outputinterface 300 a includes an outer cover layer 302 that defines aninterface surface that may be touched by a user. The outer cover layer302 is shown in cross-section.

The unified input/output interface 300 a also includes a monolithic ormulti-layer transducer substrate, identified as the transducer substrate304, positioned below the outer cover layer 302. As with otherembodiments described herein, the transducer substrate 304 can be formedfrom any number of suitable materials, including piezoelectricmaterials, electroactive polymers, magnetostrictive materials, and soon.

The transducer substrate 304 defines two surfaces, an upper surface anda lower surface. A first electrode 306 can be coupled to the uppersurface and a second electrode 308 can be coupled to the lower surface.The first electrode 306 and the second electrode 308 can be planar,sheet electrodes disposed directly onto the upper and lower surfaces ofthe transducer substrate 304 using a suitable technique such as, but notlimited to: physical vapor deposition; electroplating; electrolessplating; and so on. As a result of this construction, the controller 310can selectively electrically couple a drive circuit 312 to thetransducer substrate 304 when the unified input/output interface 300 ais operated in a drive mode or a hybrid mode. Similarly, the controller310 can selectively electrically couple a sense circuit 314 to thetransducer substrate 304 when the unified input/output interface 300 ais operated in a sense mode or a hybrid mode.

In some examples, when operating in a drive mode, the controller 310 maybe configured to disconnect and/or otherwise disable the sense circuit314 to protect the sense circuit 314 from voltages generated by thedrive circuit 312. Similarly, the drive circuit 312 can be disabled ordisconnected when the sense circuit 314 is operating.

In this manner, by selectively activating the drive circuit 312, thesense circuit 314, and different portions of the transducer substrate304, the unified input/output interface 300 a can detect localizedsingle or multi-force input, localized single or multi-touch input, andcan provide localized or generalized haptic output.

For example, in some embodiments, the first electrode 306 and the secondelectrode 308 are both segmented into corresponding arrays of individualelectrodes. The first electrode 306 can be subdivided into rows and thesecond electrode 308 can be subdivided into columns (see, e.g., FIG.5A). As a result of this construction, overlapping regions between rowsand columns can correspond to individual input sensor regions and/orindividual haptic output regions; activating a single row and a singlecolumn can drive the transducer substrate 304 at a specific locationand/or sense user input with transducer substrate 304 at a specificlocation.

In other examples, the first electrode 306 can be subdivided into a gridof individual electrodes and the second electrode 308 can be a single,planar, shielding electrode (see, e.g., FIG. 5B). As a result of thisconstruction, adjacent electrodes on the upper surface of the transducersubstrate 304 can be individual input sensors and/or individual hapticoutput regions; activating an electrode pair can drive the transducersubstrate 304 at a specific location and/or sense the transducersubstrate 304 at a specific location. In this example, the secondelectrode 308 can serve as a shield that, as one example, improves thesensing operations of the sense circuit 314.

In still further examples, the first electrode 306 can be subdividedinto a grid of individual electrodes (see, e.g., FIG. 5C) and the secondelectrode 308 can be a single, planar, ground electrode. As a result ofthis construction, overlapping regions between the individual electrodesand the ground electrode can correspond to individual input sensorsand/or individual haptic output regions; activating an individualelectrode can drive the transducer substrate 304 at a specific locationand/or sense the transducer substrate 304 at a specific location.

It is appreciated that the examples provided above are not exhaustive;other electrode patterns and subdivisions are possible. For example, insome cases, the first electrode 306—whether subdivided or otherwise—canbe a ground electrode while the second electrode 308—whether subdividedor otherwise—can be a sense electrode. In some cases, the controller 310can be configured to selectively operate different subdivisions of thefirst electrode 306 and the second electrode 308 as ground electrodes,sense electrodes, or drive electrodes. For example, in one embodiment,the controller 310 selects two electrodes that are opposite one anotheracross the body of the transducer substrate 304. In one mode, a firstelectrode is operated as a drive electrode while a second electrode isoperated as a ground electrode. In another mode, the first electrode isoperated as a ground electrode while the second electrode is operated asa drive electrode. In another mode, the first electrode can be operatedas a capacitive sense electrode while the second electrode is operatedas a shield electrode. In another mode, the first electrode can beoperated as a strain sense electrode while the second electrode isoperated as a shield electrode. In another mode, the first electrode canbe operated as a strain sense electrode while the second electrode isoperated as a reference strain sense electrode. In another mode, thefirst electrode can be operated as a strain sense electrode while thesecond electrode is operated as a reference strain sense electrode. Inanother mode, the first electrode can be operated as a primary lead of apiezoelectric sensor while the second electrode is operated as asecondary lead of the piezoelectric sensor. In another mode, the firstelectrode can be operated as a primary plate of a gap-based capacitivecompression sensor while the second electrode is operated as a referenceplate of the sensor. In another mode, the first electrode can beoperated with an adjacent electrode as a capacitive sensor while thesecond electrode is operated with an adjacent electrode as a driveelectrode. It is appreciated that the examples provided above are notexhaustive; other configurations are possible.

FIG. 3B depicts a simplified system diagram of another example of aunified input/output interface, such as described herein. In thisexample, the unified input/output interface 300 b is disposed below anouter cover layer 302 and is formed from multiple layers including ahaptic actuator layer 316 and a sensing layer 318. In this example, thehaptic actuator layer 316 and the sensing layer 318 are coplanar, butthis is not required.

The haptic actuator layer 316 and the sensing layer 318 share a commonelectrode, identified as the second electrode 308. A third electrode 320is coupled to a lower surface of the sensing layer 318. In this manner,the controller 310 can selectively couple the drive circuit 312 to thehaptic actuator layer 316 and the sense circuit 314 to the sensing layer318. As with other embodiments described herein, the three depictedelectrode layers can each be subdivided and/or segmented to definediscretely-controllable and addressable regions of the sensing layer 318and the haptic actuator layer 316. In this manner, the controller 310can be suitably configured to detect touch input (e.g., by measuringcapacitive changes with and/or between the first electrode 306, thesecond electrode 308, and/or the third electrode 320), detect forceinput (e.g., by measuring charge or voltage changes between the secondelectrode 308 and the third electrode 320), and to provide haptic output(e.g., by applying a drive signal across the haptic actuator layer 316between the first electrode 306 and the second electrode 308).

In still further examples, other configurations are possible. FIG. 3Cdepicts a simplified system diagram of another example unifiedinput/output interface, such as described herein. In this example, theunified input/output interface 300 c is disposed below an outer coverlayer 302 and is formed from multiple layers including a dielectricsensing layer 322 and a force input/haptic output layer 324. In thisexample, the force input/haptic output layer 324 and the dielectricsensing layer 322 are coplanar, but this is not required.

The force input/haptic output layer 324 and the dielectric sensing layer322 share a common electrode, identified as the second electrode 308. Athird electrode 320 is coupled to a lower surface of the forceinput/haptic output layer 324. In this manner, the controller 310 canselectively couple the drive circuit 312 to the force input/hapticoutput layer 324 and the sense circuit 314 to electrodes defined on thedielectric sensing layer 322. As with other embodiments describedherein, the three depicted electrode layers can each be subdividedand/or segmented to defined discretely-controllable and addressableregions (see, e.g., FIGS. 5A-5C) of the dielectric sensing layer 322 andthe force input/haptic output layer 324. In this manner, the controller310 can be suitably configured to detect touch input (e.g., by measuringcapacitive changes with and/or between the first electrode 306 and/orthe second electrode 308 across the dielectric sensing layer 322),detect force input (e.g., by measuring charge or voltage changes betweenthe second electrode 308 and the third electrode 320), and to providehaptic output (e.g., by applying a drive signal across the forceinput/haptic output layer 324 between the second electrode 308 and thethird electrode 320).

It may be appreciated that the foregoing description of FIGS. 2A-3C, andvarious alternatives thereof and variations thereto, are presented,generally, for purposes of explanation, and to facilitate a thoroughunderstanding of various possible configurations of a transducersubstrate of a unified input/output interface. However, it will beapparent to one skilled in the art that some of the specific detailspresented herein may not be required in order to practice a particulardescribed embodiment, or an equivalent thereof.

Thus, the foregoing and following descriptions and specific embodimentsare understood to be presented for the limited purposes of illustrationand description. These descriptions are not targeted to be exhaustive orto limit the disclosure to the precise forms recited herein. To thecontrary, it will be apparent to one of ordinary skill in the art thatmany modifications and variations are possible in view of the aboveteachings.

For example, generally and broadly, it is understood that one or morelayers of a transducer substrate can be configured for multiplepurposes. Similarly, different electrodes necessary to operate theselayers in one or more modes can be shared by adjacent layers in thestack that defines the transducer substrate.

For example, some embodiments include a shared force input/touch inputsensing layer disposed above a haptic output layer (see, e.g., FIGS.2A-2D). Other embodiments include a shared layer operable to detectforce input and touch input, and additionally operable to provide hapticoutput (see, e.g., FIG. 3A). Still further embodiments include a sharedforce input/touch input sensing layer disposed below a haptic outputlayer (see e.g., FIG. 3B). Still further embodiments include a sharedforce input/haptic output layer disposed below a touch sensing layer(see e.g., FIG. 3C). Other configurations are possible.

Furthermore, it is understood that a controller of a unifiedinput/output interface can be configured to transition between one ormore modes (e.g., a touch sense mode, a force sense mode, a hapticoutput mode, a hybrid mode, and so on) in any number of ways. FIG. 4depicts one example of a finite state diagram 400 corresponding to anoperational configuration of a controller associated with a unifiedinput/output interface, such as described herein.

The unified input/output interface depicted typically operates in aready state 402 characterized by an absence of input provided to theinterface surface. When in the ready state 402, the unified input/outputinterface operates one or more electrodes at a reduced duty cycle as acapacitive sensor in anticipation of a user touch. In some cases, thecapacitive sensor can be formed by selecting: electrodes disposed on thesame surface of a transducer substrate (coplanar mutual capacitivesensing); electrodes disposed on opposite sides of a transducersubstrate (stacked mutual capacitive sensing); individual electrodesdisposed on a surface of a transducer substrate (self-capacitivesensing); and so on. In typical examples, the ready state 402 is alower-power state (e.g., low duty cycle) than other operational statesof the unified input/output interface. As a result of thisconfiguration, the unified input/output interface can be operated atlower average power.

When in the ready state 402, if a touch is detected on the interfacesurface (e.g., via capacitive sensing), the unified input/outputinterface transitions to a touch sensing state 404. When in the touchsensing state 404, similar to the ready state 402, the unifiedinput/output interface operates one or more electrodes at an increasedduty cycle as a capacitive sensor in anticipation of receiving a userforce input and/or a user touch gesture. As a result of thisconfiguration, the unified input/output interface can quickly detectsmall changes in user touch input. In some cases, as with the readystate 402, the capacitive sensor can be formed by selecting: electrodesdisposed on the same surface of a transducer substrate (coplanar mutualcapacitive sensing); electrodes disposed on opposite sides of atransducer substrate (stacked mutual capacitive sensing); individualelectrodes disposed on a surface of a transducer substrate(self-capacitive sensing); and so on.

When in the touch sensing state 404, if a change in the touch input isdetected (e.g., change in the number of touch locations, change in areaof touch locations, change in location of touches, and so on), theunified input/output interface transitions to a touch gesture detectionstate 406 in anticipation of further changes to one or morecharacteristics of the touch input currently detected. When in the touchgesture detection state 406, the unified input/output interface isconfigured to detect touch gestures (while optionally ignoring ordisregarding force input) including, but not limited to: swipe gestures;pinch gestures; expand gestures; slide gestures; press gestures with orwithout purposeful force; click gestures; and so on.

Once a gesture is detected and/or recognized, a haptic output can beprovided by the unified input/output interface at stage 408 while theuser's finger remains in contact with the interface surface. As withother embodiments described herein, the haptic output can be a localizedor global haptic output. The haptic output can be any suitable hapticoutput such as, but not limited to: a click; a pop; a tap; a vibration;a protrusion; a shift; a translation; and so on.

While the haptic output is provided and the user's finger(s) remain incontact with the interface surface, the unified input/output interfacecan return to and/or remain in the touch gesture detection state 406. Inthis manner, if a subsequent change in the touch input is detectedadditional, different, or supplemental haptic feedback can be providedat stage 408.

However, when in the touch gesture detection state 406, if a user liftsone or more fingers (e.g., change in the number of touch locations), theunified input/output interface transitions back to the touch sensingstate 404.

In some embodiments, when in the touch sensing state 404, the unifiedinput/output system can disable force sensing circuitry and/or forcesensitive portions of the transducer substrate in order to conservepower. For example, when in the touch sensing state 404, a force sensingcircuit can be disabled, disconnected from ground, ground-shifted orbiased, or operated at a reduced duty cycle. As a result of thisconfiguration, the unified input/output interface can be operated atlower average power.

However, when in the touch sensing state 404 (and/or the touch gesturedetection state 406), if a threshold-crossing change in the forceapplied to the interface surface input is detected (e.g., a down-strokethreshold is crossed), the unified input/output interface transitions toa force sensing state 410. When in the force sensing state 410, theunified input/output interface operates one or more electrodes at anincreased duty cycle as a strain or compression sensor in anticipationof receiving a user force input and/or a user force gesture. In somecases, as with the ready state 402 and the touch sensing state 404, thestrain sensor can be formed by selecting: electrodes disposed on thesame surface of a transducer substrate (piezoelectric chargeaccumulation, strain or compression sensing, interdigitate capacitivegap strain sensing, and so on); electrodes disposed on opposite sides ofa transducer substrate (piezoelectric charge accumulation, strain orcompression sensing, vertical capacitive gap sensing, and so on); and soon.

When in the force sensing state 410, if a drop below a threshold in themagnitude of the force applied to the interface surface is detected, theunified input/output interface transitions back to the touch gesturedetection state 406 as described above.

In the alternative, when in the force sensing state 410, if a change inthe touch or force input is detected (e.g., change in the number oftouch locations, change in area of touch locations, change in locationof touches, magnitude of force applied, and so on), the unifiedinput/output interface transitions to a touch and force gesturedetection state 412 in anticipation of further changes to one or morecharacteristics of the touch input currently detected. When in the touchand force gesture detection state 412, the unified input/outputinterface is configured to detect touch gestures (including forceinformation) including, but not limited to: deep press; light press;swipe gestures; pinch gestures; expand gestures; slide gestures; pressgestures with or without purposeful force; click gestures; and so on.

Once a force and/or touch input gesture is detected and/or recognized, ahaptic output can be provided by the unified input/output interface atstage 408 while the user's finger(s) remains in contact with theinterface surface. In some cases, force sensing can be optionallydisabled at stage 414 prior to providing haptic output. As with otherembodiments described herein, the haptic output can be a localized orglobal haptic output. The haptic output can be any suitable hapticoutput such as, but not limited to: a click; a pop; a tap; a vibration;a protrusion; a shift; a translation; and so on.

While the haptic output is provided and the user's finger(s) remain incontact with the interface surface, the unified input/output interfacecan return to and/or remain in the touch and force gesture detectionstate 412. In this manner, if a subsequent change in the touch input isdetected additional, different, or supplemental haptic feedback can beprovided at stage 408.

However, when in the touch and force gesture detection state 412, if auser lifts one or more fingers (e.g., change in the number of touchlocations), the unified input/output interface transitions back to theforce sensing state 410.

It may be appreciated that the foregoing description of the statediagram in FIG. 4, and various alternatives thereof and variationsthereto are presented, generally, for purposes of explanation, and tofacilitate a thorough understanding of various possible operationalmodes or states of a controller of a unified input/output interface.However, it will be apparent to one skilled in the art that some of thespecific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, the foregoing and following descriptions and specific embodimentsare understood to be presented for the limited purposes of illustrationand description. These descriptions are not targeted to be exhaustive orto limit the disclosure to the precise forms recited herein. To thecontrary, it will be apparent to one of ordinary skill in the art thatmany modifications and variations are possible in view of the aboveteachings.

For example, generally and broadly, it is understood that a controllerof a unified input/output interface can be suitably configured totransition from and between, without limitation, a ready state, atouch-input detection state, a force-input detection state, a touchgesture recognition state, a force gesture recognition state, a touchand force gesture recognition state, a haptic output state, and so on.

Independent of a particular selected operational configuration for acontroller of a unified input/output interface described herein, it isappreciated that the transition between one or more modes may depend, tosome extent, on the layout and distribution of electrodes disposed onone or more layers of the transducer substrate. FIGS. 5A-5C depictvarious different example configurations and layouts of electrodes thatcan be disposed onto one or more surfaces of a transducer substrate suchas described herein.

FIG. 5A depicts an example distribution of electrodes for a unifiedinput/output interface. The electrode pattern 500 is typically disposedonto opposite faces of a planar body of a transducer substrate, such asa monolithic piezoelectric sheet. In this example, for simplicity ofillustration, the depicted electrodes are shown without the transducersubstrate.

In the illustrated embodiment, the electrode pattern 500 includes twosets of electrodes defining a grid. In particular, a set of columnelectrodes 502 is positioned perpendicular to a set of row electrodes504. As a result of this construction, intersections between the set ofcolumn electrodes 502 and the set of row electrodes 504 definedifferent, addressable, regions of the transducer substrate. Forexample, a controller can selectively activate one row and one column todefine a capacitive sensor at the intersection of the row and columnthat can be used by the unified input/output interface for force sensingor touch sensing. In another mode, the controller can selectivelyactivate two adjacent columns to define a mutual capacitive sensor thatcan be used by the unified input/output interface for touch sensing. Inanother mode, the controller can selectively activate a group of columnsand a group of rows to define a haptic actuator at each intersection ofeach column and each row that can be used by the unified input/outputinterface to provide localized or semi-localized haptic output.

FIG. 5B depicts another example distribution of electrodes for a unifiedinput/output interface, such as described herein. As with the embodimentdepicted in FIG. 5A, the electrode pattern 500 is typically disposed ona planar body of a transducer substrate, such as a monolithicpiezoelectric sheet. In this example, however, more than one electrodeis disposed onto a single surface of the transducer substrate; a firstelectrode 502 is shown as interdigitally engaged with a second electrode504. In this example, the first electrode 502 and the second electrode504 can form a mutual capacitive sensor suitable for detecting touchinput. In this example, the second electrode 504 extends across thefirst electrode 502 via a jumper (not labeled). The jumper may bedefined through and/or disposed on a routing insulator layer, such asthe routing insulator layer 206 depicted and described in reference toFIGS. 2A-2D

FIG. 5C depicts another example distribution of electrodes for a unifiedinput/output interface, such as described herein. As with the embodimentdepicted in FIGS. 5A-5B, the electrode pattern 500 is typically disposedon a planar body of a transducer substrate, such as a monolithicpiezoelectric sheet. In this example, as with the embodiment depicted inFIG. 5B, more than one electrode is disposed onto a single surface ofthe transducer substrate, one of which is identified as the simulatedelectrode 506.

It may be appreciated that the foregoing description of the statediagram in FIGS. 5A-5C, and various alternatives thereof and variationsthereto, are presented, generally, for purposes of explanation, and tofacilitate a thorough understanding of various possible electrodedistributions associated with a transducer substrate of a unifiedinput/output interface. However, it will be apparent to one skilled inthe art that some of the specific details presented herein may not berequired in order to practice a particular described embodiment, or anequivalent thereof. For example, in some cases, electrodes can bedisposed onto one or more surfaces—including planar surfaces, sidewallsurfaces, front surfaces, back surfaces and so on—of one or moretransducer substrate layers.

Thus, the foregoing and following descriptions and specific embodimentsare understood to be presented for the limited purposes of illustrationand description. These descriptions are not targeted to be exhaustive orto limit the disclosure to the precise forms recited herein. To thecontrary, it will be apparent to one of ordinary skill in the art thatmany modifications and variations are possible in view of the aboveteachings.

Independent of the particular electrode distribution(s) selected for aparticular embodiment, it may be appreciated that a controller may besuitably configured to selectively activate and/or deactivate one ormore electrodes (or portions of those electrodes) in order to transitionbetween one or more mode or states such as, but not limited to: touchsensing states; force sensing states; touch and force sensing states;haptic output states; haptic output and force sensing states; hapticoutput and touch input states; and so on.

In some examples, as noted above, a controller of a unified input/outputinterface can be integrated into a single circuit package, such as anintegrated circuit. An example integrated circuit system diagram isprovided in FIG. 6.

In particular, the integrated circuit package 600 can include a powermanagement controller 602 configured to receive, regulate, and/ordistribute electrical power to other components within the integratedcircuit package 600. The power management controller 602 can beconfigured to provide reset functionality, power sequencing control,brownout protection, overvoltage protection, and power management to theintegrated circuit package 600. In some embodiments, the powermanagement controller 602 can also include bandgap circuitry.

The integrated circuit package 600 can also include a touch sensingcontroller 604 that is configured to transmit signals to an electrodeconfigured to operate as a portion of a touch sensor. The touch sensingcontroller 604 is coupled, and supplied, by a single inductor multipleoutput direct current converter 606. The single inductor multiple outputdirect current converter 606 also provides input voltage to apiezoelectric drive controller 608 that is configured to transmit hapticdrive signals to an electrode configured to operate as a portion of ahaptic actuator.

The integrated circuit package 600 can also include an oscillator 610(that may include a phase lock loop or other synchronization circuitry),a direct memory access controller 612 (for storing instructions and/oroutputs from one or more controllers of the integrated circuit package600), and a waveform generator 614. The waveform generator 614 can becommunicably coupled to one or both of the touch sensing controller 604and/or the piezoelectric drive controller 608. In some cases, thewaveform generator 614 includes a memory, such as a lookup table, tostore one or more waveforms.

The integrated circuit package 600 can also include one or more sensors(labeled as the sensors 616), such as a temperature sensor. Theintegrated circuit package 600 can also include a general peripheralinput/output controller 618 for communicating with other portions,modules, or components of an electronic device incorporating theintegrated circuit package 600. In some cases, in addition to thegeneral peripheral input/output controller 618, the integrated circuitpackage 600 includes a standardized controller for input and output,such as a universal serial bus controller. The auxiliary controller isidentified as the input/output controller 620.

The integrated circuit package 600 can also include a sensing controller622. The sensing controller 622 can be configured to receive sensesignals associated with touch sensing and force sensing. The sensingcontroller 622 can be digital or analog and may include one or moredigital to analog and/or analog to digital conversion stages. In somecases, the sensing controller 622 also includes one or more filteringstages configured to increase the signal to noise ratio of the sensesignals received.

The integrated circuit package 600 can also include a general purposeprocessor 624, a general purpose memory 626, and (optionally) a generalpurpose serial port interface 628.

As noted above, the various systems and/or subsystems or modules of theintegrated circuit package 600 can be suitably communicably coupled inany number of ways. For simplicity of illustration, a high performancebus 630 is shown; it is understood that the high performance bus 630 cansuitably communicably couple any two or more of the above-referencedmodules to any other component or module, internal or external to theintegrated circuit package 600.

As noted above, it may be appreciated that the foregoing description ofthe example system diagram presented in FIG. 6, and various alternativesthereof and variations thereto, are presented, generally, for purposesof explanation, and to facilitate a thorough understanding of variouspossible modules that can be included in an integrated circuitimplementation of a controller of a unified input/output interface.However, it will be apparent to one skilled in the art that some of thespecific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.For example, in some cases, certain modules, components, controllers,and circuits mentioned above may be external to the controller.

Further embodiments reference methods for operating a unifiedinput/output interface. FIGS. 7-8 depict flowcharts including exampleoperations of methods of receiving input and providing output with aunified input/output interface.

In particular, FIG. 7 depicts a flowchart including example operationsof a method 700 of receiving touch and force input with a unifiedinput/output interface, such as described herein. As with otherembodiments described herein, the unified input/output interface caninclude a controller configured to perform, coordinate, monitor, and/orotherwise implement the method 700. The controller can be any suitablecontroller, processor, or combination of circuits such as described inreference to FIGS. 3A-3C, FIG. 4, and FIG. 6.

The method 700 includes operation 702 in which a force input isreceived. In many cases, the force input can be compared to one or morethresholds to determine whether the force input is an intentional and/orpurposeful input. In other cases, the force input can be analyzed by agesture detection controller (e.g., such as described above in referenceto FIG. 4) to determine whether the input corresponds to a force gestureinput. Next, at operation 704, force sensing circuitry can be disabledprior to providing haptic output at operation 706. In this manner, aunified input/output interface configured to receive force input and toprovide haptic output can operate a single transducer substrate (e.g.,having a body formed from a piezoelectric material) to receive bothforce input and to provide haptic output.

FIG. 8 depicts a flowchart including example operations of a method 800of providing haptic output with a unified input/output interface, suchas described herein. As with other embodiments described herein, theunified input/output interface can include a controller configured toperform, coordinate, monitor, and/or otherwise implement the method 800.The controller can be any suitable controller, processor, or combinationof circuits such as described in reference to FIGS. 3A-3C, FIG. 4, andFIG. 6.

The method 800 includes operation 802 in which a touch input isreceived. in many cases, the touch input can be compared to one or morethresholds (e.g., speed thresholds, number of fingers providing input,direction thresholds, angular thresholds, rotation thresholds, and soon) to determine whether the touch input is an intentional and/orpurposeful input. In other cases, the touch input can be analyzed by agesture detection controller (e.g., such as described above in referenceto FIG. 4) to determine whether the input corresponds to a touch gestureinput.

Next, at operation 804, a force input is received. As with theembodiment described in reference to FIG. 7, the force input can becompared to one or more thresholds to determine whether the force inputis an intentional and/or purposeful input. In other cases, the forceinput can be analyzed by a gesture detection controller (e.g., such asdescribed above in reference to FIG. 4) to determine whether the inputcorresponds to a force gesture input.

Finally, at operation 806, the total force input can be divided amongeach individual touch location. In other words, the single force inputvector can be resolved into individual vector components, eachcorresponding to a location and magnitude associated with a particulartouch input received at operation 802.

In some embodiments, the operation of resolving a force vector intomultiple components includes the operations of, in no particular order:determining a centroid of the received touch locations; determining acentroid of the received force based on output from one or more forcesensors, or force sensor locations; comparing a centroid of the touchlocations to a centroid of force locations; determining contact vectorsassociated with each touch location, initiated at the touch locationcentroid and/or the force location centroid; projecting a force vector(including the total force input as magnitude) onto one or moreindividual contact vectors; and so on. It is appreciated that a numberof suitable techniques can be used to subdivide the force input toindividual touch locations.

Further embodiments relate to techniques for selecting or determiningone or more parameters of a haptic output that can be provided by aunified input/output interface such as described herein. For example, ahaptic output provided by a unified input/output interface may be avibration. For a consistent user experience, a unified input/outputinterface may require calibration to determine a particular vibrationfrequency (or set of vibration frequencies, that may include or omitharmonics) that displaces a transducer substrate of a unifiedinput/output interface in a substantially constant manner across itsarea, based on vibratory modes of that particular transducer substrate.In other words, different transducer substrates may mechanically respondto vibrations of different frequencies, vibrating more in certainregions than in other regions. If improperly calibrated, a user touchinga first area of the unified input/output interface may perceive avibration of a different magnitude than at a second area, despite thatthe frequency of vibration is the same.

FIG. 9 depicts a flowchart including example operations of a method 900of calibrating (e.g., factory calibration, field calibration, and so on)haptic output of a unified input/output interface, such as describedherein. As with other embodiments described herein, the unifiedinput/output interface can include a controller configured to perform,coordinate, monitor, and/or otherwise implement the method 900. Thecontroller can be any suitable controller, processor, or combination ofcircuits such as described in reference to FIGS. 3A-3C, FIG. 4, and FIG.6.

The method 900 begins at operation 902 in which a transducer substrateof a unified input/output interface is operated in a haptic output mode.When in the haptic output mode, the transducer substrate is vibrated ata first drive frequency for a first time period and characteristics ofthe vibration are determined, namely, whether the first drive frequencyproduces a resonant mode in the transducer substrate. Next, a seconddrive frequency is selected (different from the first frequency) andcharacteristics of the vibration are determined. At operation 902, thedrive frequency is swept from a low frequency to a high frequency todetermine the resonant modes of the transducer substrate.

Next at operation 904, resonant modes are determined based oninformation obtained at operation 902. Once resonant modes are obtained,the resonant mode which corresponds to a low standard deviation ofdisplacement across the surface is selected at operation 906. Morespecifically, the resonant mode frequency is selected such that variancein difference between a maxima and a minima in each local region of thetransducer substrate is minimized.

As noted above, many embodiments described herein reference a unifiedinput/output interface operated in conjunction with a non-display regionof a portable electronic device. It may be appreciated, however, thatthis is merely one example; other configurations, implementations, andconstructions are contemplated in view of the various principles andmethods of operation—and reasonable alternatives thereto—described inreference to the embodiments described above.

For example, without limitation, a unified input/output interface can beadditionally or alternatively associated with: a display surface, ahousing or enclosure surface, a planar surface, a curved surface, anelectrically conductive surface, an electrically insulating surface, arigid surface, a flexible surface, a key cap surface, a trackpadsurface, a display surface, and so on. The interface surface can be afront surface, a back surface, a sidewall surface, or any suitablesurface of an electronic device or electronic device accessory.Typically, the interface surface of a unified input/output interface isan exterior surface of the associated portable electronic device butthis may not be required.

Further, although many embodiments reference a unified input/outputinterface accommodated in a portable electronic device (such as a cellphone or tablet computer) it may be appreciated that a unifiedinput/output interface can be incorporated into any suitable electronicdevice, system, or accessory including but not limited to: portableelectronic devices (e.g., battery-powered, wirelessly-powered devices,tethered devices, and so on); stationary electronic devices; controldevices (e.g., home automation devices, industrial automation devices,aeronautical or terrestrial vehicle control devices, and so on);personal computing devices (e.g., cellular devices, tablet devices,laptop devices, desktop devices, and so on); wearable devices (e.g.,implanted devices, wrist-worn devices, eyeglass devices, and so on);accessory devices (e.g., protective covers such as keyboard covers fortablet computers, stylus input devices, charging devices, and so on);and so on.

One may appreciate that, although many embodiments are disclosed above,that the operations and steps presented with respect to methods andtechniques described herein are meant as exemplary and accordingly arenot exhaustive. One may further appreciate that alternate step order orfewer or additional operations may be required or desired for particularembodiments.

Although the disclosure above is described in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied, alone or in various combinations, to one or more of the someembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments but is instead defined by the claims herein presented.

What is claimed is:
 1. A transducer substrate comprising: a rectangularbody formed from a piezoelectric material that induces anelectrically-measurable response when compressed, the rectangular bodydefining a first surface and a second surface; a set of electrodesdisposed on the first surface; a shared ground electrode disposed on thesecond surface; and a piezoelectric stack actuator positioned below therectangular body and coupled to the shared ground electrode.
 2. Thetransducer substrate of claim 1, wherein the piezoelectric stackactuator is disposed at a corner of the rectangular body and is formedas a quartered ellipse.
 3. The transducer substrate of claim 2, whereina focus of the quartered ellipse is proportionately related to a ratiobetween a width and a height of the rectangular body.
 4. The transducersubstrate of claim 1, wherein: the piezoelectric material is a firstpiezoelectric material; and the piezoelectric stack actuator comprises asecond piezoelectric material different from the first piezoelectricmaterial.
 5. The transducer substrate of claim 1, further comprising anouter cover layer disposed over the rectangular body.
 6. The transducersubstrate of claim 5, wherein the outer cover layer is formed fromglass.
 7. The transducer substrate of claim 1, wherein the set ofelectrodes comprises an array of electrodes disposed as capacitivesensors configured to detect a user touch.
 8. The transducer substrateof claim 1, wherein: the piezoelectric stack actuator is a firstpiezoelectric stack actuator disposed at a first corner of therectangular body; and the transducer substrate further comprises: asecond piezoelectric stack actuator disposed at a second corner of therectangular body; a third piezoelectric stack actuator disposed at athird corner of the rectangular body; and a fourth piezoelectric stackactuator disposed at a fourth corner of the rectangular body.
 9. Thetransducer substrate of claim 1, wherein the piezoelectric stackactuator comprises greater than three layers of piezoelectric material,each separated by a respective electrode layer.
 10. An electronic devicecomprising: a rectangular interface surface for receiving touch inputand force input from a user; a transducer substrate below therectangular interface surface and comprising: a touch and force inputlayer; a haptic output layer comprising at least two piezoelectric stackactuators positioned below and coupled to each of at least tworespective corners of the touch and force input layer; and a sharedelectrode positioned between the touch and force input layer and thehaptic output layer; and a controller coupled to the transducersubstrate and configured to operate the transducer substrate in a forcesensing mode, a touch sensing mode, and a haptic output mode; wherein:each of the at least two piezoelectric stack actuators comprises atleast three piezoelectric layers separated by at least two electrodelayers.
 11. The electronic device of claim 10, wherein the touch andforce input layer comprises: a piezoelectric body; and an array ofelectrodes disposed onto a surface of the piezoelectric body oppositethe shared electrode.
 12. The electronic device of claim 11, wherein, inthe force sensing mode, the controller is configured to select anelectrode from the array of electrodes and to measure a voltage betweenthe selected electrode and the shared electrode.
 13. The electronicdevice of claim 11, wherein, in the touch sensing mode, the controlleris configured to select a first electrode and a second electrode fromthe array of electrodes and to measure a capacitance between the firstelectrode and the second electrode.
 14. The electronic device of claim11, wherein, in the haptic output mode, the controller is configured toapply a voltage to the haptic output layer.
 15. The electronic device ofclaim 10, wherein the shared electrode is a ground electrode.
 16. Theelectronic device of claim 10, wherein the electronic device is atrackpad input device.
 17. A transducer substrate comprising: amonolithic body formed from a first piezoelectric material and defininga top surface and a bottom surface; a first electrode set coupled to thetop surface; a second electrode set coupled to the bottom surface; apiezoelectric stack actuator comprising at least two layers of a secondpiezoelectric material, the piezoelectric stack actuator disposedrelative to an edge of the monolithic body and electrically coupled toat least one electrode of the second electrode set; and a controllerelectrically coupled to the first electrode set and the second electrodeset and configured to: select a first electrode from the first electrodeset or the second electrode set; select a second electrode from thefirst electrode set or the second electrode set; and couple the firstelectrode and the second electrode to at least one of touch sensingcircuitry or force sensing circuitry.
 18. The transducer substrate ofclaim 17, wherein: the piezoelectric stack actuator comprises a thirdelectrode set; and each electrode of the third electrode set separatesat least two layers of the piezoelectric stack actuator.
 19. Thetransducer substrate of claim 18, wherein the controller is electricallycoupled to at least one electrode of the third electrode set.
 20. Thetransducer substrate of claim 19, wherein the controller is configuredto couple the at least one electrode of the third electrode set tohaptic output circuitry.